A kind of high-strength and corrosion-resistant aluminum alloy and its preparation method and application

Abstract

The invention belongs to the technical field of metal material preparation, and discloses a high-strength and corrosion-resistant aluminum alloy and its preparation method and application, including Mg 0.6-1.0%, Si 0.8-1.2%, Cu 0.1-0.3%, and Mn by weight percentage 0.4‑1.0%, Cr 0.15‑0.35%, Cd 0.05‑0.1%, and Fe≤0.5%. The present invention adds Cd, adopts three-stage homogenization heat treatment, and the Cd element is preferentially homogenized and diffused, and then the Mn and Cr elements take the Cd atomic cluster as the nucleation site, and precipitate to form a highly dispersed AlMnCr phase containing Cd elements, which can be used as a deformation regenerated phase. The nucleation particles of the crystallization realize the grain refinement of the second phase particle-induced recrystallization; the present invention optimizes the design of the aluminum alloy alloy composition based on the principle of alloying, that is, the mass ratio of Mg to Si is (0.65‑0.9):1 The mass ratio of Cu and Si is (0.15‑0.25): 1, and the Mg of highly dispersed distribution is obtained 2 Si strengthening phase and higher strength without forming a Cu-containing phase with poor corrosion resistance; through the present invention, an aluminum alloy with medium and high strength, high plasticity and high corrosion resistance can be obtained, which is suitable as an aluminum alloy for automotive structural parts or applied in its profile.

Description

technical field [0001] The invention belongs to the technical field of metal material preparation, and in particular relates to a high-strength, corrosion-resistant aluminum alloy and a preparation method and application thereof. Background technique [0002] 6xxx series aluminum alloys (i.e. Al-Mg-Si series alloys), due to their medium to high strength and high formability, have become the preferred materials for the new generation of lightweight vehicles. AA6016, AA6111 and AA6022 alloys are used in the processing of automobile body outer panels, and are widely used in body aluminum alloys. In order to improve the strength of Al-Mg-Si aluminum alloys, the content of Mg, Si, and Cu elements is usually increased, but this not only reduces the plasticity and corrosion resistance of the alloy, but also greatly reduces the processing performance of the alloy. At this time, it is usually necessary to control the content of Mg and Si elements to obtain high formability propertie...

AI Technical Summary

Problems solved by technology

At present, Sc element is the most effective rare earth element to inhibit the recrystallization of aluminum alloys, obtain non-recrystallized structure, improve alloy strength and stress corrosion resistance, but the high cost limits the industrial application of Sc-containing rare earth aluminum alloys

However, the ultra-fine-grained material can be obtained by equal-diameter angular extrusion (ECAP), but the plasticity of the alloy has not been effectively improved, and it is not easy for industrial production.

Images